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The available Metadata types are: String, Int, Double, Bool, Euler, Vector3, Vector4, Quaternion, Matrix, Box3, Curve, Image and Mesh.
There's also an array type for all these metadatas.
The most powerful metadata is are the MapMetadata , (a map container for mixed type of metadatas.) and the ArrayMetadata (a vector container for mixed type of metadatas)
Metadatas are most useful when used in conjunction with custom python and C++ Behaviour Modules.
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